Sidney ii



(No Model.)

S. H. SHORT. ARMATURE FOR DYNAMO ELECTRIC MACHINES.

No 475,159. Patented May 17, 1892.

U NITED STATES PATENT O EIc SIDNEY H. SHORT, OF CLEVELAND, OHIO, ASSIGNOR TO THE SHORT ELECTRIC RAIIAVAY COMPANY, OF SAME PLACE.

ARMATURE FOR DYNAMO-ELECTRIC MACHINES.

SPECIFICATION forming part Of Letters Patent No. 475,159, dated May 17, 1892.

Application filed November 6, 1890. Serial No. 370,540- (No model.)

To all whom it may concern:

Be it known that I, SIDNEY H. SHORT, of Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Armatures for DynamoElectric Generators; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will onable others skilled in the art to which it appertains to make and use the same.

My invention has reference to improvements in armatures for dynamo-electricgenerators and electric motors, and it has more special reference to the construction of the cores of such armatures and to the manner of assembling the parts thereof and connecting them with each other and with the hub of the armature, although myinvention is more particularly adapted to the construction of armatures of the Pacinott-i or Gramme type. It may also be used with advantage in the construction of armatures of the Siemens and other types.

The main object of my invention is to so construct the armature-core that its magnetic potential may be very high and may shift with great rapidity without unduly heating the core, and with the view to securing this object I construct the armature-core of laminae of soft iron, which are not in direct magnetic contact with each other. These laminae I assemble and fasten together by rivets or bolts of non-magnetic material passing through the laminae parallel to the axis of the core, and the ring-core thus produced I connect with the hub-spiders by bolts which are either also made of non-magnetic material, or if made of magnetic material are not in magnetic contact With the laminate, so that the core is composed of aseries of magnetic plates which are in a great measure magnetically independent of each other, are easily saturrated magnetically, and are capable of shifting their poles with great rapidity, whereby the magnetic inertia of the whole core is reduced to a minimum. In dynamo-electric generators and motors provided with such cores the practical line of commutation is very nearly coincident with the theoretical line of commutation and the heating of the core is reduced to a minimum. In addition thereto by my improved construction I can and do provide for an effective ventilation of the core and for a definite spacing of the armature-coils. From the following detailed description all this will more fully appear with reference to the accompanying drawings, which form a part thereof and in which I have illustrated an en'ibodiment of my said invention.

Figure 1 represents a face view of one of the magnetic laminae of my improved armature; Fig. 2, an end view of an arm ature constructed in accordance with my invention with parts broken away and other parts in section. Fig. 3 represents a longitudinal section of my improved armature.

Like numerals of reference indicate like parts throughout all the drawings.

In accordance with my improvement the core is built up of laminae 1, made of soft sheet-iron and shaped, as shown in Fig. 1, as a ring or annulus, having rectangular recesses 2 formed in its outer edge, as shown. These recesses 2, which are designed to receive the armatu re-coils, are separated from each other by the teeth or projections 3, which at the same time form the side walls of the recesses. By preference, although not necessarily so, these rectangular recesses are formed in groups in the circumference of each laminae, and in the drawings I have shown four such groups, each'occupying approximately a quadrant of the circle and each group separated from the other by a somewhat larger tooth or projection l. It will now be seen that if a great number of such magnetic laminae are piled up in such manner that the recesses and projections of each correspond to the recesses and projections of all the others there will be obtained a heavy ring, having in its outer periphery a number of properly-spaced rectangular channels corresponding to the recesses 2, which channels will be partitioned off by ridges or walls formed by the teeth or projections 3 and 4. In thus building up the armature-ring I interpose small washers 6, of paperor other like material, on the rivet-bolts 6, which are made of copper or other non-magnetic material and serve to secure together the several laminze composing the core. I also place similar washers 6 around the bolts which connect the core with the hubs. The core thus built up of laminze, riveted together and separated by thewashers, is then wound with the coils, and 15 provided with hubs 9 9, secured to the core in the following manner:

Fromeach hub extend a number of radial arms 10, which at theirouter ends merge into a run 11, which latter is broad enough to cover the end of the armature-ring, or nearly so, and spacing-blocks 12 are interposed between the rims 11 and the ends of the core at the points where the groups of channels are separated from each other by the enlarged teeth or projections at of the iron laminze, and bolts 13, passing through the rims 11, the spacingblocks 12, and through the iron laminae of the core securely fasten the hubs to said core. For this purpose holes 14 are fortned in the iron laminae, as shown in Fig. 1. These bolts 13, if made of iron, are covered with a layer 13' of non-magnetic material and preferably of insulating material; but if made of nonmagnetic material-such as copperthey may remain bare, and in either case they are screwthreaded at each end and are there provided with nuts 15.

The Washers 6' and (i serve not only to separate the lamina: of its eore,but also serve to form air-spaces between the several magnetic laminae, affording an effective ventilation and cooling of the satne should they be come at all heated by the shifting of their magnetic poles or by the very slight Foucault currents which may be generated in the laminze.

It will be understood that the magnetic laminae formed, as shown in Fig. 1,with their recesses and projections and with the holes 7 and 14 all accurately spaced maybe assembled for the formation of an armature-core with very great rapidity, and when riveted together the laminated core may be handled like a solid piece, the coils wound upon the same, and the hubs bolted to it with great comfort.

The hubs 9, with the arms 10 merging into the rims 11, are preferably made of non-magnetic material having great strength-as, for instance, of German silver, aluminium, or aluminium bronzeand the armature-shaft 16 is keyed to the hubs, as usual, and the armatu re is mounted between the pole-pieces 1718 of the field-magnets in the ordinary manner.

In an armature thus constructed each magnetic lamina of the same behaves practically like an independent magnetic system, owing to the fact that there is no magnetic contact between the successive laminze at any point, as would be the case if the rivets and bolts used for assembling the laminae were of iron and the bolts forsecuring the hubs to the core were also of iron, in which case the magnetic inertia of the whole core would be equal to the sum of the magnetic inertia of its laminzc, while in my construction the n'tagnetic inertia of the whole core is only equal to that of a single lamina.

Having fully described my invention, what I claim as new, and desire to secure by Letters Patent, is

A ring-armature consisting of a core composed of magnetically-independent laminae, rivets extending through the laminze, and insulating washers encircling the rivets and separating the latninze, in combination with end pieces, each consisting of an annulus and a hub joined by radial arms, spacing-blocks interposed between the end pieces and core, bolts passing through the end pieces, spacingblocks and lamina}, and insulating-washers encircling the bolts and separating the laminze, substantially as set forth.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

S. H. SHORT.

\Vitnesses:

A. B. CALHOUN, G. J. LEEPHART. 

